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Objective: To identify and describe populations at risk for HIV in 3 clinical research centers in Kenya and South Africa., Design: Prospective cohort study., Methods: Volunteers reporting recent sexual activity, multiple partners, transactional sex, sex with an HIV-positive partner, or, if male, sex with men (MSM; in Kenya only) were enrolled. Sexually active minors were enrolled in South Africa only. Risk behavior, HIV testing, and clinical data were obtained at follow-up visits., Results: From 2005 to 2008, 3023 volunteers were screened, 2113 enrolled, and 1834 contributed data on HIV incidence. MSM had the highest HIV incidence rate of 6.8 cases per 100 person-years [95% confidence interval (CI): 4.9 to 9.2] followed by women in Kilifi and Cape Town (2.7 cases per 100 person-years, 95% CI: 1.7 to 4.2). No seroconversions were observed in Nairobi women or men in Nairobi or Cape Town who were not MSM. In 327 MSM, predictors of HIV acquisition included report of genital ulcer (Hazard Ratio: 4.5, 95% CI: 1.7 to 11.6), not completing secondary school education (HR: 3.4, 95% CI: 1.6 to 7.2) and reporting receptive anal intercourse (HR: 8.2, 95% CI: 2.7 to 25.0). Paying for sex was inversely associated with HIV infection (HR: 0.2, 95% CI: 0.04 to 0.8). 279 (13.0%) volunteers did not return after the first visit; subsequent attrition rates ranged from 10.4 to 21.8 volunteers per 100 person-years across clinical research centers., Conclusions: Finding, enrolling, and retaining risk populations for HIV prevention trials is challenging in Africa. African MSM are not frequently engaged for research, have high HIV incidence, need urgent risk reduction counseling, and may represent a suitable population for future HIV prevention trials.

This paper compares and contrasts number of partners and condom use behaviour for female sex workers and a sample of women working in other economic activities, with both samples drawn from the large informal settlement of Kibera, Nairobi. As expected, univariate analysis revealed much higher numbers of overall sexual partners and higher levels of condom use among female sex workers compared to Kibera women in other occupations. An unexpected finding, however, was that female sex workers with a romantic partner had significantly fewer sexual partners per unit time than female sex workers without such a partner. This finding held for multivariate analysis, with negative binomial regression analyses showing that having a romantic partner was significantly associated with reductions in total number of both sexual partners overall and with sexual partners who did not use condoms. In contrast, HIV status, education, number of immediate family members and levels of alcohol consumption were non-significant factors for both regression analyses. Results suggest that female sex workers' romantic partners act as more than sources of possible HIV infection; rather, romantic partners appear to have an important positive impact on health. We discuss this finding in light of possible harm-reduction programmes focusing on female sex workers and their romantic partners.

Background: We evaluated predictors of consistent condom use among female sex workers (FSWs), a core group for controlling the spread of HIV., Methods: In an analysis of data collected in 2004-2005 from 140 Kenyan FSWs who completed questionnaires administered during a baseline study visit and three bimonthly follow-up visits, we used a case-crossover design to identify predictors of consistent condom use during all coital acts in the preceding 2 weeks, overall and by partner type., Results: Participants (n=140) completed the baseline visit and 390 bimonthly follow-up visits. Alcohol use during sex was negatively associated with consistent condom use with helping partners (defined as regular sex partners to whom the woman could go for help or support if needed) (adjusted odds ratio [AOR], 2.6, 95% confidence interval [CI] 1.0-6.5) but not associated with condom use with other partners. Coital frequency was associated with condom use with other partners only. Women who reported 1-5 (AOR 11.0, 95% CI 4.3-28.3) or 6-9 recent coital acts (AOR 3.8, 95% CI 1.7-8.8) with other partners were more likely to report consistent condom use with those partners than were women who reported ≥10 acts. Having a recent partner delay payment was inversely associated with consistent condom use with helping, other, or all partners., Conclusions: Correlates of consistent condom use differed by partner type. By using a case-crossover design, we were able to identify potentially modifiable factors associated with consistent condom use by FSWs who used condoms consistently with a given partner type during some periods but not others.

Changes in the rates of condom use and number of sexual partners were evaluated among 140 female sex workers in Kibera, Kenya, participating in a 6-month study of diaphragm safety and acceptability for prevention of sexually transmitted infections conducted in 2004-2005. Analyses were stratified by partner type. Multivariable Tobit regression modeling was used to assess the association between study visit and proportion of acts protected. Participants completed 140 baseline visits and 390 bimonthly follow-up visits. The mean percentage of coital acts reported as protected by a condom increased from 56% at baseline to 68% at the 6-month visit (P < 0.01). Similar increases were observed for condom use by all partner types. Additionally, the mean number of sexual partners decreased over the study. Furthermore, consistent (i.e., 100%) diaphragm use during follow-up was associated with a higher proportion of coital acts protected by a condom in analyses adjusted for study visit and coital frequency. These findings suggest that, despite concerns that introduction of the diaphragm would result in more risky sexual behaviors, reported condom use increased and number of partners decreased.

Objectives: HIV-neutralizing immunoglobulin A (IgA) and HIV-specific cellular immunity have been described in highly exposed, persistently seronegative (HEPS) individuals, but well controlled studies have not been performed. We performed a prospective, nested case-control study to examine the association of genital IgA and systemic cellular immune responses with subsequent HIV acquisition in high-risk Kenyan female sex workers (FSWs)., Design and Methods: A randomized trial of monthly antibiotic prophylaxis to prevent sexually transmitted disease/HIV infection was performed from 1998 to 2002 in HIV-uninfected Kenyan FSWs. After the completion of trial, FSWs who had acquired HIV (cases) were matched 1: 4 with persistently uninfected controls based on study arm, duration of HIV-seronegative follow-up, and time of cohort enrolment. Blinded investigators assayed the ability at enrolment of genital IgA to neutralize primary HIV isolates as well as systemic HIV-specific cellular IFNgamma-modified enzyme-linked immunospot and proliferative responses., Results: The study cohort comprised 113 FSWs: 24 cases who acquired HIV and 89 matched controls. Genital HIV-neutralizing IgA was associated with reduced HIV acquisition (P = 0.003), as was HIV-specific proliferation (P = 0.002), and these associations were additive. HIV-specific IFNgamma production did not differ between case and control groups. In multivariable analysis, HIV-neutralizing IgA and HIV-specific proliferation each remained independently associated with lack of HIV acquisition. Genital herpes (HSV2) was associated with increased HIV risk and with reduced detection of HIV-neutralizing IgA., Conclusion: Genital HIV-neutralizing IgA and systemic HIV-specific proliferative responses, assayed by blinded investigators, were prospectively associated with HIV nonacquisition. The induction of these immune responses may be an important goal for HIV vaccines.

Objectives: Female sex workers (FSWs) form a core group at high risk of both sexual HIV acquisition and secondary transmission. The magnitude of these risks may vary by sexual risk taking, partner HIV prevalence, host immune factors and genital co-infections. We examined temporal trends in HIV prevalence and per-act incidence, adjusted for behavioral and other variables, in FSWs from Nairobi, Kenya., Methods: An open cohort of FSWs followed since 1985. Behavioral and clinical data were collected six monthly from 1985 to 2005, and sexually transmitted infection (STI) diagnostics and HIV serology performed. A Cox proportional hazards model with time-dependent covariables was used to estimate infection risk as a function of calendar time., Results: HIV prevalence in new FSW enrollees peaked at 81% in 1986, and was consistently below 50% after 1997. Initially uninfected FSWs remained at high risk of acquiring HIV throughout the study period, but the rate of HIV acquisition during unprotected sex with a casual client declined by over four-fold. This reduction correlated closely with decreases in gonorrhea prevalence, and predated reductions in the Kenyan HIV population prevalence by over a decade., Conclusions: The per-act rate of HIV acquisition in high-risk Nairobi FSWs fell dramatically between 1985 and 2005. This decline may represent the impact of improved STI prevention/therapy, immunogenetic shifts in at-risk women, or changes in the proportion of HIV exposures occurring with clients who had acute HIV infection. Declining HIV incidence in high-risk cohorts may predict and/or be causally related to future reductions in population prevalence.

Background: Women in sex work stand to benefit if the contraceptive diaphragm alone or combined with a microbicide proves to be an effective barrier method against HIV and sexually transmissible infection (STI). Currently, contraceptive diaphragm users are advised to leave the diaphragm in situ without concomitant use of other intravaginal substances for at least 6 h after intercourse., Methods: We conducted in-depth interviews on sexual behaviour including post-coital intravaginal practices with 36 women in sex work and 26 of their clients and held two focus-group discussions, each with 10 women., Results: The women described adapting several potentially harmful substances, such as cloth and soapy water, for post-coital vaginal use to ensure personal hygiene, disease prevention and client pleasure. Some wanted to clean themselves and remove the diaphragm early, fearing exposure to HIV infection for themselves and their subsequent clients. Clients indicated their desire for 'dry sex', vaginal cleanliness and reduced risk of infection through vaginal cleaning., Conclusions: The diaphragm as a female-controlled barrier method for HIV/STI prevention may have limited acceptability among women in sex work if its effectiveness depends on a 6-h post-coital wait before removal, along with avoidance of concomitant use of intravaginal substances. In keeping with the beliefs of the the female sex workers and their needs and practices, alternative intravaginal substances and modes of insertion that will not disrupt vaginal flora, injure vaginal epithelium, damage the diaphragm or counteract potentially beneficial effects of microbicides are needed. The possibility of removing the diaphragm sooner than the recommended 6 h for contraception should be further studied.

Background: Female sex workers (FSWs) often lack the ability to negotiate safer sex and are at high risk for HIV-1 infection and sexually transmitted infections (STIs)., Methods: Seronegative FSWs were enrolled in an STI/HIV-1 prevention trial in Nairobi, Kenya. Demographics and sexual risk taking were assessed every 3 months. Predictors of reduced risk taking were defined using multivariate logistic regression., Results: Four hundred sixty-six FSWs were enrolled and followed for just over 2 years each. A spectrum of sex work was apparent: FSWs working in night clubs were younger, charged more for sex, and used condoms more frequently; FSWs working from home were older, charged less, and used condoms the least; and those working in bars were intermediate. Increases in reported condom use were most significant and sustained for FSWs working from home and charging less for sex and were poorly maintained for bar-based FSWs. Self-reported lower condom use, higher client numbers, and alcohol use were associated with higher STI rates., Conclusions: Home-based FSWs and those charging less for sex used condoms the least at baseline but showed the greatest and most sustained improvements over time. Potential response heterogeneity in FSW subgroups should be considered in the design of HIV-1 prevention programs.

Objective: To assess the association between vaginal douching and sexually transmitted infections (STI) among a group of female sex workers (FSWs) in Nairobi, Kenya., Methods: This study was part of a randomised, placebo controlled trial of monthly prophylaxis with 1 g of azithromycin to prevent STIs and HIV infection in a cohort of Nairobi FSWs. Consenting women were administered a questionnaire and screened for STIs., Results: The seroprevalence of HIV-1 among 543 FSWs screened was 30%. HIV infection was significantly associated with bacterial vaginosis (BV), trichomoniasis, gonorrhoea, and the presence of a genital ulcer. Regular douching was reported by 72% of the women, of whom the majority inserted fluids in the vagina, generally after each sexual intercourse. Water with soap was the fluid most often used (81%), followed by salty water (18%), water alone (9%), and a commercial antiseptic (5%). Douching in general and douching with soap and water were significantly associated with bacterial vaginosis (p = 0.05 and p = 0.04 respectively). There was a significant trend for increased frequency of douching and higher prevalence of BV. There was no direct relation observed between douching and risk for HIV infection or other STIs., Conclusion: The widespread habit of douching among African female sex workers was confirmed. The association between vaginal douching and BV is of concern, given the increased risk of HIV infection with BV, which has now been shown in several studies. It is unclear why we could not demonstrate a direct association between douching and HIV infection. Further research is required to better understand the complex relation between douching, risk for bacterial vaginosis, and risk for HIV and other STIs.

Our objectives were to describe the baseline findings of a trial of antibiotic prophylaxis to prevent sexually transmitted infections (STIs) and HIV-1 in a cohort of Nairobi female sex workers (FSWs). A questionnaire was administered and a medical examination was performed. HIV-negative women were randomly assigned to either one gram azithromycin or placebo monthly. Mean age of the 318 women was 32 years, mean duration of sex work 7 years and mean number of clients was 4 per day. High-risk behaviour was frequent: 14% practised anal intercourse, 23% sex during menses, and 3% used intravenous drugs. While 20% reported condom use with all clients, 37% never use condoms. However, STI prevalence was relatively low: HIV-1 27%, bacterial vaginosis 46%, Trichomonas vaginalis 13%, Neisseria gonorrhoeae 8%, Chlamydia trachomatis 7%, syphilis 6% and cervical intraepithelial neoplasia (CIN) 3%. It appears feasible to access a population of high-risk FSWs in Nairobi with prevention programmes, including a proposed trial of HIV prevention through STI chemoprophylaxis.

Background: Accurate predictions of HIV-1 incidence in potential study populations are essential for designing HIV-1 vaccine efficacy trials. Little information is available on the estimated incidence of HIV-1 in such populations, especially information on incidence over time and incidence while participating in risk-reduction programs., Objectives: To examine time trends in HIV-1 incidence in a vaccine preparedness cohort., Design: Prospective cohort study of female prostitutes in Mombasa, Kenya., Methods: HIV-1 incidence was determined using open and closed cohort designs. Generalized estimating equations were used to model HIV-1 and sexually transmitted disease (STD) incidence and sexual risk behaviors over time., Results: When analyzed as a closed cohort, HIV-1 incidence declined 10-fold during 3 years of follow-up (from 17.4 to 1.7 cases/100 person-years; p <.001). More than 50% of the cases of HIV-1 occurred during the first 6 months after enrollment, and 73% during the first 12 months. When analyzed as an open cohort, HIV-1 incidence density fell during the first 4 calendar years, influenced by accumulation of lower risk participants and variations in study recruitment. Significant declines occurred in both STD incidence and high-risk sexual behaviors during follow-up., Conclusions: This study documents a dramatic decline in the risk of HIV-1 infection while participating in a prospective cohort, with most seroconversions occurring within 1 year of enrollment. Variations in HIV-1 incidence within high-risk populations should be anticipated during the design of vaccine trials.

Certain human leukocyte antigens, by presenting conserved immunogenic epitopes for T cell recognition, may, in part, account for the observed differences in human immunodeficiency virus type 1 (HIV-1) susceptibility. To determine whether HLA polymorphism influences HIV-1 susceptibility, a longitudinal cohort of highly HIV-1-exposed female sex workers based in Nairobi, Kenya, was prospectively analyzed. Decreased HIV-1 infection risk was strongly associated with possession of a cluster of closely related HLA alleles (A2/6802 supertype; incidence rate ratio [IRR], 0.45; 95% confidence interval [CI], 0.27-0.72; P=.0003). The alleles in this supertype are known in some cases to present the same peptide epitopes for T cell recognition. In addition, resistance to HIV-1 infection was independently associated with HLA DRB1*01 (IRR, 0.22; 95% CI, 0.06-0.60; P=.0003), which suggests that anti-HIV-1 class II restricted CD4 effector mechanisms may play an important role in protecting against viral challenge. These data provide further evidence that resistance to HIV-1 infection in this cohort of sex workers is immunologically mediated.

Objectives: Most HIV-1 transmission is sexual; therefore, immune responses in the genital mucosa may be important in mediating protection against HIV infection. This study examined HIV-1-specific mucosal IgA in a cohort of HIV-1-resistant Kenyan female sex workers., Methods: HIV-1-specific immune responses were compared in HIV-1-resistant and HIV-1-infected sex workers, and in lower risk uninfected women. Cervical and vaginal samples from each group were tested for HIV-1-specific IgA and IgG by enzyme immunoassay. Systemic T-helper lymphocyte cell responses to HIV-1 envelope peptide epitopes were assayed using an interleukin 2 bioassay. HIV-1 risk-taking behaviours were assessed using standardized questionnaires., Results: HIV-1-specific IgA was present in the genital tract of 16 out of 21 (76%) HIV-1-resistant sex workers, five out of 19 (26%) infected women, and three out of 28 (11%) lower risk women (P < 0.0001). Among lower risk women, the presence of HIV-1-specific IgA was associated with HIV-1 risk-taking behaviour. Systemic T-helper lymphocyte responses to HIV-1 envelope peptides were present in 11 out of 20 (55%) HIV-1-resistant women, four out of 18 (22%) infected women, and one out of 25 (4%) lower risk women (P < 0.001). T-helper lymphocyte responses did not correlate with the presence or titre of virus-specific mucosal IgA in any study group., Conclusions: HIV-1-specific IgA is present in the genital tract of most HIV-1-resistant Kenyan sex workers, and of a minority of lower risk uninfected women, where it is associated with risk-taking behaviour. These data suggest a role for mucosal HIV-1-specific IgA responses in HIV-1 resistance, independent of host cellular responses.

Background and Objectives: Genital ulcer disease (GUD) is a major risk factor for human immunodeficiency virus (HIV) transmission. Cross-sectional studies have suggested that HIV infection may itself predispose to genital ulceration (GU)., Goal: To prospectively study the effects of HIV type 1 (HIV-1) infection and behavioral variables on GU incidence., Methods: A cohort of 302 Kenyan female sex-workers was established in April 1991. Women were scheduled for assessment every 2 weeks, and bloods were collected every 6 months for HIV serology, rapid plasma reagin (RPR) and CD4 counts. Logistic regression was used to study risk factors for incident genital ulcers., Results: 189 women (62.5%) had at least one incident ulcer over 24.3 +/- 15.3 months. GU incidence was higher in seropositive than initially seronegative women (82% vs. 48%; odds ratio [OR]) = 4.33; P < 0.01). Only HIV-1 seropositivity (OR = 3.42), a CD4 count < 200/ml (OR = 1.94), and oral contraceptive use (OR = 1.35) were associated (P < 0.05) with GU incidence in regression analysis. For those ulcers where an etiology was actively sought, Hemophilus ducreyi was confirmed in 54 (19%) of cases, and syphilis in 30 (29%)., Conclusion: GU incidence in Kenyan sex workers is independently affected by HIV-1 serostatus, degree of immunosuppression, and oral contraceptive use.

Background: There is indirect evidence that HIV-1 exposure does not inevitably lead to persistent infection. Heterogeneity in susceptibility to infection could be due to protective immunity. The objective of this study was to find out whether in highly HIV-1-exposed populations some individuals are resistant to infection., Methods: We did an observational cohort study of incident HIV-1 infection-among 424 initially HIV-1-seronegative prostitutes in Nairobi, Kenya, between 1985 and 1994. 239 women seroconverted to HIV-1 during the study period. Exponential, Weibull, and mixture survival models were used to examine the effect of the duration of follow-up on incidence of HIV-1 infection. The influence of the duration of exposure to HIV-1 through prostitution on seroconversion risk was examined by Cox proportional hazards modelling, with control for other known or suspected risk factors for incident HIV-1 infection. HIV-1 PCR with env, nef, and vif gene primers was done on 43 persistently seronegative prostitutes who remained seronegative after 3 or more years of follow-up., Findings: Modelling of the time to HIV-1 seroconversion showed that the incidence of HIV-1 seroconversion decreased with increasing duration of exposure, which indicates that there is heterogeneity in HIV-1 susceptibility or acquired immunity to HIV-1. Each weighted year of exposure through prostitution resulted in a 1.2-fold reduction in HIV-1 seroconversion risk (hazard ratio 0.83 [95% CI 0.79-0.88], p < 0.0001). Analyses of epidemiological and laboratory data, show that persistent seronegativity is not explained by seronegative HIV-1 infection or by differences in risk factors for HIV-1 infection such as safer sexual behaviours or the incidence of other sexually transmitted infections., Interpretation: We conclude that a small proportion of highly exposed individuals, who may have natural protective immunity to HIV-1, are resistant to HIV-1.

Peer-mediated education programs in Kenya and Zimbabwe focusing on female sex workers for the control of human immunodeficiency virus (HIV) infection and other sexually transmitted diseases (STDs) have led to increased condom use and increased adoption of other safer sex practices, as well as declines in STD and HIV incidence among female sex workers. It is likely that similar declines have occurred among their clients and possibly in the general community, although supporting data are limited. These results are encouraging. However, progress in increasing the scale and coverage of intervention programs among female sex workers has been slow. Constraints to expanding program coverage include inadequate political commitment; deficiencies in program planning, management, and human resources; and insufficient funding. The challenges currently are to show that behavioral change can be sustained and to scale up activities from small demonstration projects to district, provincial, and national levels.

Studies from Kenya have reported rapid clinical disease progression among HIV-infected professional sex workers. The reasons for this rapid decline are unknown. To better understand factors influencing the course of disease, HIV-1 disease progression was explored in terms of declines in CD4 counts. Two samples from Nairobi, Kenya, were studied, one from a cohort of female sex workers and another, as a comparison group, from mothers enrolled in an HIV-1 vertical-transmission study. A Markov model was used to analyze transitions between HIV-1 disease stages as defined by CD4 counts. It appears that sex workers experience a rapid decline in CD4 counts, consistent with earlier findings of rapid clinical disease progression among individuals in this group. The rate of decline in CD4 counts among the mothers appears to be lower. It is speculated that either intensive exposure to sexually transmitted pathogens or infection with several strains of HIV-1 may account for the rapid disease progression among female sex workers.

From a cohort of female sex workers in Nairobi, Kenya, 163 women were observed to seroconvert to human immunodeficiency virus type 1 (HIV-1) and followed to study progression to HIV-1-related disease. The effect of several covariables on disease progression was studied using a Weibull proportional hazards model. The Weibull survival model was fitted to the observed incubation times. Estimates of the median duration to CDC stage IV-A and IV-C disease were 3.5 and 4.4 years, respectively. Condom use before seroconversion was associated with a reduced risk of CDC stage IV-A disease (relative risk = .64, P < .05). The incubation time of HIV-1-related disease is extremely short in this population.

To determine the frequency and duration of antibody-negative human immunodeficiency virus (HIV) infection among heterosexually exposed African women, 56 HIV-seronegative female prostitutes in Nairobi were studied. Polymerase chain reaction (PCR) was used to detect HIV DNA in peripheral blood at enrollment, and women were followed prospectively with serologic testing to determine HIV seroincidence. Six women (11%) were infected with HIV by PCR criteria at enrollment. Seroconversion occurred in 5 of these subjects within 1-12 months, while the sixth remained seronegative when last evaluated at 5 months. The cumulative annual seroconversion rate in the entire cohort was 38%. Using maximum likelihood analysis, the mean interval between HIV infection and seroconversion was estimated to be between 3 and 4 months, similar to that described for homosexual men and blood product recipients in the United States. Prolonged HIV infection in the absence of antibodies appears to be uncommon in this setting.

Objective: To determine the efficacy of the nonoxynol 9 contraceptive sponge in preventing sexual acquisition of the human immunodeficiency virus (HIV)., Design: Prospective, randomized placebo-controlled trial., Setting: Research clinic for prostitutes in Nairobi, Kenya., Patients and Interventions: One hundred thirty-eight HIV-seronegative women were enrolled, of whom 74 were assigned to nonoxynol 9 sponge use and 64 to placebo use. These two groups did not significantly differ with respect to demographic characteristics, sexual practices, or prevalence of genital infections at enrollment, except for a lower number of sex partners per week and a higher initial prevalence of genital ulcers among women assigned to nonoxynol 9 sponge use. Among the 116 women who returned for follow-up, the mean durations of follow-up were 14 and 17 months for the two groups, respectively., Main Outcome Measure: HIV seroconversion., Results: Nonoxynol 9 sponge use was associated with an increased frequency of genital ulcers (relative risk [RR], 3.3; P less than .0001) and vulvitis (RR, 3.3; P less than .0001) and a reduced risk of gonococcal cervicitis (RR, 0.4; P less than .0001). Twenty-seven (45%) of 60 women in the nonoxynol 9 sponge group and 20 (36%) of 56 women in the placebo group developed HIV antibodies. The hazard ratio for the association between nonoxynol 9 sponge use and HIV seroconversion was 1.7 (95% confidence interval [CI], 0.9 to 3.0). Using multivariate analysis to control for the presence of genital ulcers at enrollment, the adjusted hazard ratio for the association between nonoxynol 9 sponge use and seroconversion was 1.6 (95% CI, 0.8 to 2.8)., Conclusions: Genital ulcers and vulvitis occurred with increased frequency in nonoxynol 9 sponge users. We were unable to demonstrate that nonoxynol 9 sponge use was effective in reducing the risk of HIV infection among highly exposed women.

To evaluate the impact of human immunodeficiency virus (HIV) on human papillomavirus (HPV) and cervical intraepithelial neoplasia (CIN), a study was conducted of 147 HIV-seropositive and 51 HIV-seronegative prostitutes in Nairobi, Kenya. Among the women infected with HIV, 10 (7%) had signs or symptoms of significant HIV-related disease, and the remaining 93% were asymptomatic. The prevalence of cervical HPV DNA was 37% among HIV-seropositive women and 24% in HIV-seronegative women (odds ratio [OR] 1.7, 95% confidence intervals [CI] 0.8, 3.6, after adjusting for potential confounding factors). Genital warts, cervical HPV DNA, and cytologic findings consistent with CIN were all significantly associated with younger age and fewer years of prostitution, but were unrelated or weakly related to number of sexual partners per week or frequency of condom use. In a subset of 63 women with evaluable Papanicolaou smears, CIN was found in 50% of the women with HPV but only in 8% of those without HPV (adjusted OR 7.2, 95% CI 1.6, 32.1, P = 0.006). However, CIN was unrelated to HIV seropositivity (prevalence of 26% among HIV-seropositive women and 24% in HIV-seronegative women). Among women with cervical HPV DNA, HIV infection was not associated with an increased prevalence of CIN (47% prevalence among women with HIV versus 57% prevalence among women without HIV). Thus, in this population of HIV-seropositive women, most of whom had CDC Stage II or III infection, there was no demonstration of an adverse impact of HIV on CIN.

Control of genital ulcer disease (GUD) is a proposed intervention to slow the dissemination of human immunodeficiency virus (HIV) infection. Programs for the control of sexually transmitted diseases (STD) should focus on groups of high-frequency transmitters, such as prostitutes and their clientele. This study illustrates the interaction between the prevalence of chancroid, use of barrier prophylaxis against STDs, and HIV infection in a population of female prostitutes in Nairobi. Four hundred and twenty three women were evaluated. Despite the increased use of condoms, the prevalence of genital ulcers remained constant between 1986-87 and 1987-88. Genital ulcer disease was simultaneously associated with HIV infection (adjusted odds ratio: 3.7, P less than .01) whereas it was independently and inversely associated with more consistent condom use (P less than .01). The authors conclude that genital ulcer disease can be controlled in these populations but concurrent HIV infection increases the difficulty of this intervention.

A cohort of 418 lower socioeconomic strata prostitutes were enrolled in a study of the epidemiology of sexually transmitted diseases (STDs) between January and April 1985. Sixty-two per cent of the women were seropositive for HIV infection at enrollment. Significant associations were found between HIV seropositivity and Tanzanian origin (OR = 2.12, CI 95% = 1.18-3.81, P less than 0.03), younger age, a shorter duration of prostitution, reduced fecundity, use of oral contraceptives (OR = 1.8, CI 95% = 1.1-2.9, P less than 0.05) and genital ulcer disease (OR = 3.32, P less than 0.00001). No associations were noted with other STD. Stepwise logistic regression analysis confirmed independent associations between HIV infection and Tanzanian origin (OR = 2.27, CI 95% = 1.25-4.14, P less than 0.007), reduced fecundity (OR = 0.83, CI 95% = 0.74-0.94, P less than 0.003), oral contraceptive use (OR = 2.02, CI 95% = 1.22-3.35, P less than 0.006) and duration of prostitution (OR = 0.39, CI 95% = 0.23-0.65, P less than 0.004). Oral contraceptives may increase susceptibility to HIV or may be a marker for other factors which increase risk of acquisition. Further studies are necessary to confirm this association.

Condom use was assessed after a programme of education about the acquired immunodeficiency syndrome and a condom distribution programme in a well-characterised prostitute population in Nairobi. Women received their education at group meetings (barazas) and at individual counselling sessions during which they were given the results of serological tests for the human immunodeficiency virus (group 1) or at barazas only (group 2), or through very little of either (group 3). During the counselling sessions free condoms were distributed. Before either of the programmes started, 10%, 9%, and 7% of groups 1, 2, and 3 women, respectively, reported occasional use of condoms. By November 1986, 80%, 70%, and 58% of groups 1, 2, and 3 women, respectively, reported at least some condom use. The mean frequency of condom use was 38.7 (SD 31.8)%, 34.6 (34.5)%, and 25.6 (29.5)% of sexual encounters in groups 1, 2, and 3 women. 20 of 28 women who were non-condom-users seroconverted compared with 23 of 50 women who reported some use of condoms.

Recent epidemiologic studies have implicated genital/anorectal ulcer disease as an important cofactor for acquisition and transmission of human immunodeficiency virus (HIV) during sexual intercourse. To better understand the mechanism for the association between genital ulcers and HIV, exudates from 62 genital ulcers of 56 HIV-seropositive prostitutes in Nairobi (Kenya) were cultured for HIV. Twenty-six ulcer cultures could not be evaluated for the presence of HIV because of bacterial or fungal contamination. HIV was isolated from 4 (11%) of the 36 remaining uncontaminated ulcer cultures (2 introital, 1 vaginal, and 1 cervical) from 4 separate women. HIV was isolated from the cervical os from only 2 of the 4 women. HIV p24 antigen was detected in exudate from 1 of the 4 culture-positive ulcers and 0 of 32 culture-negative ulcers. Genital ulcers in seropositive patients should be regarded as potential sources of HIV, which could be important in transmission of HIV during intercourse. Public health measures aimed at controlling sexually transmitted genital ulcer diseases should be an integral part of acquired immunodeficiency syndrome (AIDS) prevention programs.